Consideration for input current-ripple reduction on a novel pulse-link DC-AC converter for fuel cells

Authors have proposed a novel DC-AC converter topology for fuel cells, which includes a novel method for the reduction of input current-ripple. In general, the current- ripple in fuel cells give s damage to the fuel cell consumption and life span because the chemical reaction time is much slower than the commercial power source frequency. Therefore, the input current-ripple should be reduced in the DC-AC converter for fuel cells. In the conventional DC-AC converter, a large capacitor is inserted between the boost converter stage and the PWM inverter stage for the current- ripple reduction. This capacitor disturbs the size reduction of the converter unit. In the proposed topology, the first- stage boost converter provides a series of boosted voltage pulses directly to the second-stage PWM inverter. Therefore, a large capacitor for the smoothed DC power source is not needed. Instead, a series-connected LC circuit is inserted for the current-ripple reduction. This paper focuses the mechanism of current-ripple reduction. Moreover, an active method for the current-ripple reduction is proposed, which reduces the input current-ripple less than 1 Amp.